The invention relates to bird feeders made accessible only to birds below a desired weight.
Heretofore, various attempts have been made to provide bird feeders with weight responsive devices intended to discourage animals, such as squirrels, and large birds from attempting to gain access to feed intended exclusively for small birds. As by way of example, reference may be had to U.S. Pat. Nos. 2,230,058; 2,918,901; 3,104,649, 3,164,130; 3,241,525 and 4,407,839.
While the constructions disclosed by these prior patents appear capable of performing their intended purpose, they are believed to have the disadvantage of being overly complex or cumbersome to manufacture and maintain.